Re: VOTE: Changing completions-common-part face's default

[Stefan Monnier]

> So let's choose 3:1 as a threshold for that use.  Certainly
> blue3 (1.87) and  blue4 (1.27) don't clear that bar, so let's
> ditch those.

Having a lot of contrast between `default` and `completions-common-part`
is an explicit non-goal for this first step because we want
`completions-common-part` not to get in your face in the typical
basic/prefix-completion.


        Stefan